The present invention relates to electrochemical machining of workpieces and, more particularly, it relates to apparatus for electro-erosive or electrical discharge machining of workpieces. The invention can be utilized in electrochemical machining, copying and piercing machines, as well as in burring machines.
All the above mentioned types of machines have protective devices or guards to protect the operator and to minimize the waste of the electrolyte, caused by splashing and evaporation.
It is a known practice to have protective boards or guards mounted in the front part of a burring machine, which boards or guards are manually closed before a working cycle is started.
In other known cases, the protecting device includes a casing directly connected with the electrode and movable jointly therewith.
In the last-mentioned structure exhaust ventilation can be effected exclusively with aid of a suction exhaust hood overlying the machine, which, however, would not afford reliably enough protection of the operator from toxic vapors and fumes produced during the working operation; moreover, the structure calls for a relatively high capacity of the suction exhaust system. Besides, this structure creates draft-like air streams about the operator, which impairs the sanitary conditions of the latter's work.
There is further known an apparatus for electrochemical machining of workpieces, comprising a work table, a stationary crossbeam and a movable one, an exhaust device and an electrolyte splashing-preventing device. The movable crossbeam with the electrode secured thereon is movable toward a workpiece to be machined, accommodated in a device fastened on the work table, under the action of a drive mounted on the stationary crossbeam, with the electrode thus being moved toward and away from the workpiece. The exhaust device is communicated with the ventilation conduit.
This last-described structure in multi-station arrangements for electrochemical machining of workpieces is operable only with the capacity of the exhaust device being stepped up as many times as there are the stations in the arrangement. Furthermore, the exhaust device is operative also while the workpieces are either positioned or removed, creating draft-like air streams about the operator. Among the disadvantages of the structure is the fact that the guard door is to be opened and closed when the workpieces are either positioned or removed.